Mr Norris, 20, accepted in court that the person driving his car, a blue Peugeot 106, was responsible for slashing Gatri Hassan's face last November. Mr Norris told the court he had lent his car to 22-year-old David Norris on the day of the attack.
Under cross examination, an agitated Mr Norris was asked whether either he or David Norris had been responsible for the attack in Downham Lane, Bromley, south-east London, on the evening of 29 November. He said: "It could have been David. I don't know. It wasn't me."
After the incident Mr Norris was arrested and told detectives he had been the only male person to drive the car that day.
But appearing yesterday on charges of unlawful wounding and possessing an offensive weapon, a knife, he maintained his brother David had the car.
He told the court the car had been picked up by his brother outside the flat of Gary Dobson, another Lawrence suspect. He said that at the time Mr Hassan was wounded, around 9.15pm, he was at the home of his girlfriend.
The stabbing of Mr Hassan took place on the road where Mr Dobson had his flat. A group of young men, who were believed to be with Clifford Norris, pulled him off his victim after the attack.
Mr Norris, wearing a grey suit, blue shirt and grey tie, was asked by prosecuting counsel Francis Sheridan to say why he lied to police. He replied: "I had a good reason to lie, I was protecting my brother because I lent him my car that night, I don't know what happened that night. I was protecting him as anyone else would - he is my brother.
"I am not saying that my brother had the car at 9.15 and I am not saying that he never had the car at 9.15. I don't know, I wasn't there."
Asked whether David Norris had "confessed" about the attack to him, Mr Norris responded: "I have asked him, he says he has never done anything about it. I don't know if it was David - all I do know is that it wasn't me."
Giving alibi evidence Mr Norris's girlfriend, Toni Power, of Mottingham, south-east London, said he had been with her at the time of the assault.
But the victim, Mr Hassan, a mechanic, said that on the evening he was attacked he was driving along when a blue Peugeot 106 sped up behind him, overtook him on the wrong side of the road and slammed on the brakes. A little further along the road, this was repeated.
The drivers of both vehicles got out and, Mr Hassan says, the man he later identified as Clifford Norris approached with a knife in his right hand, "with a blade at least six inches long".
Mr Hassan stated he was struck on the right eye. He said: "After the first blow, I lost vision, then I felt another blow. I felt my eyebrow slice open. I didn't see what caused it, but I felt blood on my face."
Mr Hassan has said he heard "a name being mentioned" which he recognised. He agreed earlier that he was aware of the name Norris in connection with the Stephen Lawrence enquiry.
Summing up, Mr Sheridan said the reason Clifford Norris did not come out with a defence that his brother had been lent the car was because he was at first unaware Mr Hassan had memorised the registration of the Peugeot, which made him the prime suspect as he was, by his own admission, the only male driver of the vehicle.
The case continues.